CVE-2025-62800
6.1 · MEDIUMOverview
CVE-2025-62800 is a medium-severity vulnerability affecting jlowin fastmcp. It was published on October 28, 2025 and has a CVSS 3.1 base score of 6.1 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 6.1, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical Description
FastMCP is the standard framework for building MCP applications. Versions prior to 2.13.0 have a reflected cross-site scripting vulnerability in the OAuth client callback page (oauth_callback.py) where unescaped user-controlled values are inserted into the generated HTML, allowing arbitrary JavaScript execution in the callback server origin. The issue is fixed in version 2.13.0.
Remediation
Check the references section for vendor advisories and patches from jlowin. Update fastmcp to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| jlowin | fastmcp | >= 0, < 2.13.0 | Affected |
Frequently Asked Questions
What is CVE-2025-62800?
CVE-2025-62800 is a medium-severity vulnerability affecting jlowin fastmcp. It was published on October 28, 2025 and has a CVSS 3.1 base score of 6.1 (MEDIUM).
How severe is CVE-2025-62800?
This vulnerability has a CVSS 3.1 base score of 6.1, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2025-62800?
Check the references section for vendor advisories and patches from jlowin. Update fastmcp to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2025-62800?
CyberStrike's AI-powered security agents can automatically detect CVE-2025-62800 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
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